CVE-2026-90273

Reference-count leak via skipped perf error cleanup

Published Sep 17, 2026 · Updated Sep 17, 2026

Reference-count leakage in Linux 5.15 CoreSight ETM4x allows local users to leave tracing configurations marked active via perf errors. The perf enable path skips cscfg_csdev_disable_active_config() when branch broadcast is unsupported or etm4_enable_hw() fails, leaving config_desc->active_cnt elevated. Reaching the defect requires access to perf tracing on applicable CoreSight hardware; the published mechanism establishes a counter leak, not a documented crash, reboot, or data disclosure.

CVSS severity3.3
Low
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reference-count leakage in Linux 5.15 CoreSight ETM4x allows local users to leave tracing configurations marked active via perf errors. The perf enable path skips cscfg_csdev_disable_active_config() when branch broadcast is unsupported or etm4_enable_hw() fails, leaving config_desc->active_cnt elevated. Reaching the defect requires access to perf tracing on applicable CoreSight hardware; the published mechanism establishes a counter leak, not a documented crash, reboot, or data disclosure.

The record

CVE
CVE-2026-90273
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.15
  2. Affected versionversion=810ac401db1fe432020d7936a199591000de8279 <0a47f0be6557b4a851addd430383a4dc7ee08752
  3. Affected versionversion=810ac401db1fe432020d7936a199591000de8279 <7e4f2702bbadbde887a5d8897297720a7f037ee5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=810ac401db1fe432020d7936a199591000de8279 <0a47f0be6557b4a851addd430383a4dc7ee08752; version=810ac401db1fe432020d7936a199591000de8279 <7e4f2702bbadbde887a5d8897297720a7f037ee5

Published CVSS scores

3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
3.3SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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